Hi All, I've problem on my iMac g5 2006 A1200 with intel core 2 duo 2.16 GHz related with power supply or logic board, I'm not sure. I read on how to diagnostic the 4 led light and follow the instructions. Here are what I found on my imac; 1.Plug the cord in the outlet, I'm sure that both sources are good. I noticed the #1 LED are green for 3 sec follow by #2 and #3, then they all turn off, no green light. 2.I pressed the power button in the back, nothing happens. 3.What is the next thing I should check before saying because of bad power supply. Since AC inlet is pretty hard to access, how do I know if it still work or not after take it out?. 4.I read from apple site that we can turn on imac using internal power button but I can't find it. Please advices/suggestions are welcome. noom.